Improved active noise control performance based on Laguerre lattice

An improved active noise control (ANC) system that exploits the orthogonalization of the input narrowband noise field, both for the main path identification and the noise canceller for the error path identification, is proposed. This is achieved by a joint Laguerre lattice structure, which uses a common Laguerre lattice filter and different regression filters for the main path identification and for noise canceller for error path identification. Further, for the adaptation of both regression filters, use of the overall errors instead of individual errors (at each stage of the lattice) is suggested, as it provides better reduction in the convergence error. Compared to the existing ANC systems based on lattice structure, the proposed ANC has a significantly faster convergence rate (7 times) and the use of overall error over individual errors, provides better noise reduction. Further, the Laguerre structure used for the lattice, reduces the computational load significantly (requires only about half the normal filter length).